Conductor wire and circuit board. Since before 1980 technicians installing telephone and data circuits have terminated the ends of insulated wires in circuit boards having connectors of the insulation displacement type. Connectors of that type have electrical contact members which form a pair of blade-like cutting edges occupying a common plane with a V-shaped space between them. When the end of an insulated conductor wire is pushed down between the blade-like members, their sharp cutting edges cut through the insulation and sufficiently into the metal that the circuit board contact is then in electrically conductive engagement with the conductor wire. At the same time, some insulation surrounding the contact area is purposely left in place to protect the contacts against moisture and corrosion.
Wire Termination Tool. It has been standard practice to use a wire termination tool with a metal tool body that also carries a blade, for inserting the wire end between the connector contacts; or alternatively, for inserting the wire end between the connector contacts while concurrently cutting off a protruding end of the conductor wire. One standard type of such a wire termination tool is known as a “110 Blade”, and another standard type is known as a “66 Blade”. While those two types of tools are somewhat differently shaped to work with differently shaped connector panels, their function is essentially the same. A conductor wire to be attached to the connection panel is placed across the front of the termination tool. The wire termination tool is then driven forward to insert the conductor wire between corresponding insulation displacement knife blade contacts and to seat the wire; or to seat the wire and concurrently cut off a protruding end of the wire.
Impact Driver or Punch-Down Tool. A hand-operated impact driver of the type shown in the Gregson patent has now become the industry standard for driving either a 110 Blade or a 66 Blade. The hand-operated driver or impact tool has a housing for slidably receiving the termination tool. The termination tool, whether a 110 Blade, 66 Blade, or other industry standard type blade, is slidably mounted within or upon the driver. The punch-down or impact driver tool contains an internal drive spring which becomes compressed when the tradesman or technician applies hand force. A factory setting on the impact tool allows either of two positions of an adjustable cam to select either a short or a longer compressed lengths for the drive spring and thereby a high or low impact force, respectively.
Compression Spring Drive Action. A forward end of the conductor wire to be inserted into the connector panel is placed across the forward end of the wire termination tool. The force of the compression spring bears against the termination tool. The technician or tradesman pushes the impact tool forward, and when the pre-set force level is reached a mechanical trigger associated with the spring then automatically releases the drive spring compression. The stored energy of the compression spring then drives the 110 or 66 Blade or other standard tool forward to insert the conductor wire into the connector of the circuit panel. At this time the technician or tradesman would be holding the impact tool steady, so as to achieve the exact impact for which the pre-set spring compression was selected. Typically, although not necessarily, the forward movement of the termination tool also concurrently cuts off a protruding end of the wire, by means of a cutting blade carried on the tool.
Abrupt release. Thus according to standard practice a spring that is pre-compressed, and then by manual force further compressed to a predetermined level, is abruptly released by a mechanical trigger to drive the termination tool. The release of the spring force and its resulting momentum, and additional force applied manually by the operator, will then drive the termination tool member forward to seat the conductor wire within the connector and also to cut off its protruding end.
“Sweet Spot” for Optimum Contact. In the typical connectors of the insulation displacement type the pair of knife blades that achieve the electrical contact with a conductor wire inserted between them have defined characteristics. The blades are not entirely stiff and immobile, but are so constructed as to have a desired amount of spring action. In some installations the conductor wire is electrically connected to the panel but does not need to be cut off, and remains an active electrical conductor in both directions from the connector panel. The configuration of the knife blades provides an optimum location where it is preferred to have the conductor lodge. This may be referred to as the “sweet spot”. If a conductor wire is not inserted far enough to reach the “sweet spot” the electrical contact may be inferior. And if the conductor wire is pushed in too far, there may be significant damage to the connector or to the panel on which it is mounted. Desired product design is such that if a conductor is correctly inserted at the “sweet spot” it should be possible to remove that conductor and insert a different one, for dozens or perhaps hundreds of times, without damage to the connector panel.
Connector Materials. An insulated conductor wire is usually composed of two materials; an outer polymer insulator and an inner diameter of copper, both of which are relatively soft and rather easy to cut. The connector block and its associated circuitry usually contain copper, thin plastic, and fiberglass materials that would be easily damaged, thus establishing a need for great precision in inserting a conductor wire into the connector.
Meeting Diverse Standards. The present invention is directed to obtaining precise results in inserting conductor wires into a circuit panel of the insulation displacement type. During recent years, due largely to the deregulation of the industry, many manufacturers have made all of the relevant products—the connector circuit panels, the insulated conductors attached to the panels, and the tools for accomplishing the attachment—to differing and non-uniform technical standards. Due to those differences in standards for the products of different companies the previously accepted industry-wide standards for wire insertion are no longer reliable. The force level required for cutting off the end of a conductor wire may be somewhat greater or somewhat less than the force level required to insert that wire between a pair of contact knives. If too low a spring compression level is used, the conductor wire may not become conductively seated to the full extent that is desired. If too high a compression level is used, there is a danger that the delicate mechanism of the connection panel circuit board may be damaged. Neither is desirable. For a particular connector and particular wire type the optimum force level that would be needed to seat the conductor wire properly within the contacts of the connector panel can be determined with reasonable accuracy. For a particular connector and particular wire type the force level that would be required to cut off the protruding wire end can also be determined with reasonable accuracy.